1.Curcumin extraction and preparation and optimization of curcumin nanoparticles
Yuhang WANG ; Han ZHANG ; Chaojing ZHANG ; Xurong KOU ; Tongtong JING ; Rimei LIN ; Xinyu LIU ; Shilei LOU ; Hui YAN ; Cong SUN
Chinese Journal of Tissue Engineering Research 2026;30(2):362-374
BACKGROUND:Curcumin is the main active ingredient of turmeric and has significant medicinal value in anti-tumor,anti-inflammatory,antioxidant and other aspects.However,its poor water solubility,unstable chemical properties and easy decomposition lead to difficulty in extracting curcumin and low extraction yield.Therefore,it is particularly important to optimize the curcumin extraction method.OBJECTIVE:To enhance the extraction yield and utilization value of curcumin and optimize the curcumin extraction process and curcumin nanoparticle preparation process.METHODS:Curcumin was extracted from turmeric by ethanol extraction,ultrasonic extraction,ionic liquid extraction,enzyme extraction,and ionic liquid combined with ultrasonic assisted enzyme extraction.The curcumin extraction yield was detected by high performance liquid chromatography;the best extraction method was determined,and subsequent process optimization experiments were carried out.The curcumin extraction yield was the response value with the type of ionic liquid,reaction temperature,ultrasonic time,liquid-to-solid ratio,ionic liquid concentration,and enzyme-drug mass ratio as parameters.The optimal production process of ionic liquid combined with ultrasonic assisted enzyme extraction was determined by single factor combined response surface experiment.The optimal process for preparing curcumin nanoparticles by ionic crosslinking method was determined by single factor combined response surface experiment with acetic acid concentration,chitosan to sodium tripolyphosphate mass ratio,stirring rate,curcumin mass concentration,sodium tripolyphosphate mass concentration,and chitosan mass concentration as parameters,and drug encapsulation efficiency as response value.Curcumin nanoparticles were prepared under the optimal process,and the particle size,polydispersity index,Zata potential value,drug loading,stability,hemolysis rate,and antioxidant capacity in vivo and in vitro of the nanoparticles were detected.RESULTS AND CONCLUSION:(1)Among the five extraction methods,the curcumin yield of ionic liquid combined with ultrasound-assisted enzyme extraction was the highest,and this method was selected as the curcumin extraction method for subsequent experiments.The results of single factor combined response surface experiment showed that the optimal process for curcumin extraction was:ionic liquid selected 1-hexyl-3-methylimidazolium chloride,reaction temperature 55 ℃,liquid-to-solid ratio 40 mL/g,ultrasound time 57 minutes,ionic liquid concentration 57%,enzyme-drug mass ratio 3.5:10,and the obtained turmeric extraction yield was 3.10%.The optimal preparation process of curcumin nanoparticles was:glacial acetic acid concentration 0.5%,chitosan and sodium tripolyphosphate mass ratio 5.0:1,stirring speed 150 r/min,curcumin mass concentration 2.23 mg/mL,sodium tripolyphosphate mass concentration 1.45 mg/mL,chitosan mass concentration 3.63 mg/mL,and the obtained drug encapsulation efficiency was 90.61%.(2)The drug loading of curcumin nanoparticles was(14.49±0.23)%,the average particle size was(76.95±1.65)nm,the polydispersity coefficient was 0.15±0.02,and the Zata potential value was(32.37±1.46)mV.The curcumin nanoparticles had good stability and blood compatibility,did not induce hemolysis,and had stronger antioxidant capacity in vivo and in vitro than free curcumin.(3)The results show that the process optimization not only solves the problems of low extraction yield,poor solubility,and low bioavailability of curcumin,but also enhances its antioxidant activity in vivo and in vitro.
2.Curcumin extraction and preparation and optimization of curcumin nanoparticles
Yuhang WANG ; Han ZHANG ; Chaojing ZHANG ; Xurong KOU ; Tongtong JING ; Rimei LIN ; Xinyu LIU ; Shilei LOU ; Hui YAN ; Cong SUN
Chinese Journal of Tissue Engineering Research 2026;30(2):362-374
BACKGROUND:Curcumin is the main active ingredient of turmeric and has significant medicinal value in anti-tumor,anti-inflammatory,antioxidant and other aspects.However,its poor water solubility,unstable chemical properties and easy decomposition lead to difficulty in extracting curcumin and low extraction yield.Therefore,it is particularly important to optimize the curcumin extraction method.OBJECTIVE:To enhance the extraction yield and utilization value of curcumin and optimize the curcumin extraction process and curcumin nanoparticle preparation process.METHODS:Curcumin was extracted from turmeric by ethanol extraction,ultrasonic extraction,ionic liquid extraction,enzyme extraction,and ionic liquid combined with ultrasonic assisted enzyme extraction.The curcumin extraction yield was detected by high performance liquid chromatography;the best extraction method was determined,and subsequent process optimization experiments were carried out.The curcumin extraction yield was the response value with the type of ionic liquid,reaction temperature,ultrasonic time,liquid-to-solid ratio,ionic liquid concentration,and enzyme-drug mass ratio as parameters.The optimal production process of ionic liquid combined with ultrasonic assisted enzyme extraction was determined by single factor combined response surface experiment.The optimal process for preparing curcumin nanoparticles by ionic crosslinking method was determined by single factor combined response surface experiment with acetic acid concentration,chitosan to sodium tripolyphosphate mass ratio,stirring rate,curcumin mass concentration,sodium tripolyphosphate mass concentration,and chitosan mass concentration as parameters,and drug encapsulation efficiency as response value.Curcumin nanoparticles were prepared under the optimal process,and the particle size,polydispersity index,Zata potential value,drug loading,stability,hemolysis rate,and antioxidant capacity in vivo and in vitro of the nanoparticles were detected.RESULTS AND CONCLUSION:(1)Among the five extraction methods,the curcumin yield of ionic liquid combined with ultrasound-assisted enzyme extraction was the highest,and this method was selected as the curcumin extraction method for subsequent experiments.The results of single factor combined response surface experiment showed that the optimal process for curcumin extraction was:ionic liquid selected 1-hexyl-3-methylimidazolium chloride,reaction temperature 55 ℃,liquid-to-solid ratio 40 mL/g,ultrasound time 57 minutes,ionic liquid concentration 57%,enzyme-drug mass ratio 3.5:10,and the obtained turmeric extraction yield was 3.10%.The optimal preparation process of curcumin nanoparticles was:glacial acetic acid concentration 0.5%,chitosan and sodium tripolyphosphate mass ratio 5.0:1,stirring speed 150 r/min,curcumin mass concentration 2.23 mg/mL,sodium tripolyphosphate mass concentration 1.45 mg/mL,chitosan mass concentration 3.63 mg/mL,and the obtained drug encapsulation efficiency was 90.61%.(2)The drug loading of curcumin nanoparticles was(14.49±0.23)%,the average particle size was(76.95±1.65)nm,the polydispersity coefficient was 0.15±0.02,and the Zata potential value was(32.37±1.46)mV.The curcumin nanoparticles had good stability and blood compatibility,did not induce hemolysis,and had stronger antioxidant capacity in vivo and in vitro than free curcumin.(3)The results show that the process optimization not only solves the problems of low extraction yield,poor solubility,and low bioavailability of curcumin,but also enhances its antioxidant activity in vivo and in vitro.
3.Effects of human umbilical cord-derived mesenchymal stem cell therapy for cavernous nerve injury-induced erectile dysfunction in the rat model.
Wei WANG ; Ying LIU ; Zi-Hao ZHOU ; Kun PANG ; Jing-Kai WANG ; Peng-Fei HUAN ; Jing-Ru LU ; Tao ZHU ; Zuo-Bin ZHU ; Cong-Hui HAN
Asian Journal of Andrology 2025;27(4):508-515
Stem cell treatment may enhance erectile dysfunction (ED) in individuals with cavernous nerve injury (CNI). Nevertheless, no investigations have directly ascertained the implications of varying amounts of human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) on ED. We compare the efficacy of three various doses of HUC-MSCs as a therapeutic strategy for ED. Sprague-Dawley rats (total = 175) were randomly allocated into five groups. A total of 35 rats underwent sham surgery and 140 rats endured bilateral CNI and were treated with vehicles or doses of HUC-MSCs (1 × 10 6 cells, 5 × 10 6 cells, and 1 × 10 7 cells in 0.1 ml, respectively). Penile tissues were harvested for histological analysis on 1 day, 3 days, 7 days, 14 days, 28 days, 60 days, and 90 days postsurgery. It was found that varying dosages of HUC-MSCs enhanced the erectile function of rats with bilateral CNI and ED. Moreover, there was no significant disparity in the effectiveness of various dosages of HUC-MSCs. However, the expression of endothelial markers (rat endothelial cell antigen-1 [RECA-1] and endothelial nitric oxide synthase [eNOS]), smooth muscle markers (alpha smooth muscle actin [α-SMA] and desmin), and neural markers (neurofilament [RECA-1] and neurogenic nitric oxide synthase [nNOS]) increased significantly with prolonged treatment time. Masson's staining demonstrated an increased in the smooth muscle cell (SMC)/collagen ratio. Significant changes were detected in the microstructures of various types of cells. In vivo imaging system (IVIS) analysis showed that at the 1 st day, the HUC-MSCs implanted moved to the site of damage. Additionally, the oxidative stress levels were dramatically reduced in the penises of rats administered with HUC-MSCs.
Male
;
Animals
;
Erectile Dysfunction/metabolism*
;
Rats, Sprague-Dawley
;
Mesenchymal Stem Cell Transplantation/methods*
;
Rats
;
Penis/pathology*
;
Humans
;
Disease Models, Animal
;
Umbilical Cord/cytology*
;
Peripheral Nerve Injuries/complications*
;
Mesenchymal Stem Cells
;
Nitric Oxide Synthase Type III/metabolism*
;
Actins/metabolism*
;
Nitric Oxide Synthase Type I/metabolism*
4.Glucocorticoid Discontinuation in Patients with Rheumatoid Arthritis under Background of Chinese Medicine: Challenges and Potentials Coexist.
Chuan-Hui YAO ; Chi ZHANG ; Meng-Ge SONG ; Cong-Min XIA ; Tian CHANG ; Xie-Li MA ; Wei-Xiang LIU ; Zi-Xia LIU ; Jia-Meng LIU ; Xiao-Po TANG ; Ying LIU ; Jian LIU ; Jiang-Yun PENG ; Dong-Yi HE ; Qing-Chun HUANG ; Ming-Li GAO ; Jian-Ping YU ; Wei LIU ; Jian-Yong ZHANG ; Yue-Lan ZHU ; Xiu-Juan HOU ; Hai-Dong WANG ; Yong-Fei FANG ; Yue WANG ; Yin SU ; Xin-Ping TIAN ; Ai-Ping LYU ; Xun GONG ; Quan JIANG
Chinese journal of integrative medicine 2025;31(7):581-589
OBJECTIVE:
To evaluate the dynamic changes of glucocorticoid (GC) dose and the feasibility of GC discontinuation in rheumatoid arthritis (RA) patients under the background of Chinese medicine (CM).
METHODS:
This multicenter retrospective cohort study included 1,196 RA patients enrolled in the China Rheumatoid Arthritis Registry of Patients with Chinese Medicine (CERTAIN) from September 1, 2019 to December 4, 2023, who initiated GC therapy. Participants were divided into the Western medicine (WM) and integrative medicine (IM, combination of CM and WM) groups based on medication regimen. Follow-up was performed at least every 3 months to assess dynamic changes in GC dose. Changes in GC dose were analyzed by generalized estimator equation, the probability of GC discontinuation was assessed using Kaplan-Meier curve, and predictors of GC discontinuation were analyzed by Cox regression. Patients with <12 months of follow-up were excluded for the sensitivity analysis.
RESULTS:
Among 1,196 patients (85.4% female; median age 56.4 years), 880 (73.6%) received IM. Over a median 12-month follow-up, 34.3% (410 cases) discontinued GC, with significantly higher rates in the IM group (40.8% vs. 16.1% in WM; P<0.05). GC dose declined progressively, with IM patients demonstrating faster reductions (median 3.75 mg vs. 5.00 mg in WM at 12 months; P<0.05). Multivariate Cox analysis identified age <60 years [P<0.001, hazard ratios (HR)=2.142, 95% confidence interval (CI): 1.523-3.012], IM therapy (P=0.001, HR=2.175, 95% CI: 1.369-3.456), baseline GC dose ⩽7.5 mg (P=0.003, HR=1.637, 95% CI: 1.177-2.275), and absence of non-steroidal anti-inflammatory drugs use (P=0.001, HR=2.546, 95% CI: 1.432-4.527) as significant predictors of GC discontinuation. Sensitivity analysis (545 cases) confirmed these findings.
CONCLUSIONS
RA patients receiving CM face difficulties in following guideline-recommended GC discontinuation protocols. IM can promote GC discontinuation and is a promising strategy to reduce GC dependency in RA management. (Trial registration: ClinicalTrials.gov, No. NCT05219214).
Adult
;
Aged
;
Female
;
Humans
;
Male
;
Middle Aged
;
Arthritis, Rheumatoid/drug therapy*
;
Glucocorticoids/therapeutic use*
;
Medicine, Chinese Traditional
;
Retrospective Studies
5.Clinical effects of Supplemented Buyang Huanwu Decoction on postoperative patients with lumbar vertebral fracture complicated with spinal cord injury due to Qi Deficiency and Blood Stasis Pattern
Jia-man YANG ; Tong LIU ; De-hui FAN ; Mei-yi SU ; Ying LIN ; Man-guang LIANG ; Zhi-wen OU ; Shun-cong ZHANG
Chinese Traditional Patent Medicine 2025;47(11):3630-3634
AIM To explore the clinical effects of Supplemented Buyang Huanwu Decoction on postoperative patients with lumbar vertebral fracture complicated with spinal cord injury due to Qi Deficiency and Blood Stasis Pattern.METHODS One hundred and twenty patients were randomly assigned into control group(60 cases)for 6-week intervention of conventional treatment,and observation group(60 cases)for 6-week intervention of both Supplemented Buyang Huanwu Decoction and conventional treatment.The changes in clinical effects,TCM syndrome scores,spinal cord conduction signals(SEP amplitude,MEP amplitude),serum neurotrophic factors(NGF,IGF-1,BDNF),coagulation and inflammatory indices(PT,APTT,TNF-α,IL-1 β)and incidence of adverse reactions were detected.RESULTS The observation group demonstrated higher total effective rate than the control group(P<0.05).After the treatment,the two groups displayed decreased TCM syndrome scores,TNF-α,IL-1β(P<0.05),increased spinal cord conduction signals,coagulation and inflammatory indices(P<0.05),and shortened PT,APTT(P<0.05),especially for the observation group(P<0.05).No significant difference in incidence of adverse reactions was found between the two groups(P>0.05).CONCLUSION For the patients with lumbar vertebral fracture complicated with spinal cord injury due to Qi Deficiency and Blood Stasis Pattern,Supplemented Buyang Huanwu Decoction can safely and effectively promote neurological function recovery.
6.Correlation analysis between FO with spiral CT measurement and prognosis of percutaneous-assisted superior capsulotomy approach for THA
Changzeng LIU ; Jianjie MAO ; Cong CHEN ; Xiaopeng LI ; Hui CHU
China Medical Equipment 2025;22(10):61-65
Objective:To explore the clinical application value of the measured femoral offset(FO)based on three-dimensional modeling of spiral computed tomography(CT)in percutaneous-assisted superior capsulotomy approach for total hip arthroplasty(THA).Methods:A total of 92 patients with fractures at hip joint who underwent percutaneous-assisted superior capsulotomy approach for THA at the 904th Hospital of People's Liberation Army Joint Service Support Force between January 2023 and June 2024 were prospectively enrolled.According to the preoperative FO median(34.8 mm)that was measured by CT,these patients were divided into high-FO group(n=46)and low-FO group(n=46).Postoperative outcomes between two groups,which included bone density T value(T value),FO value,external tilt angle and forward tilt angle of mortar cup,and the deviation of femoral stem alignment,as well as the scores of Harris Hip Score(HHS),Visual Analog Scale(VAS),positive rate of Trendelenburg sign and incidence of complication,were compared.Results:The preoperative bone density T value of high-FO group was(-1.1±0.7),which was higher than(-1.3±0.8)of low-FO group,and the difference was not significant(P>0.05).The FO was(38.5±3.4)mm in high-FO group,which was lower than(30.9±2.7)in low-FO group,and the difference was significant(t=12.356,P<0.001).The external tilt angle and forward tilt angle of mortar cup,and the deviation of femoral stem alignment of high-FO group were respectively(42.6±3.9)°,(16.8±2.6)° and(1.1±0.7)mm,which were lower than(43.4±4.1)°,(17.5±3.0)° and(1.3±0.8)mm of low-FO group,and the differences were not significant(P>0.05).The HHS scores at the 1st,3rd,6th and 12th month after surgery in high-FO group were significantly better than those of low-FO group,and the differences were significant(t=3.104,4.772,6.358,7.326,P<0.05).The VAS scores at the 3rd and 12th month after surgery in high-FO group were significantly lower than those in low-FO group,and the difference was significant(t=-9.215,-7.582,P<0.05).The positive rate of Trendelenburg sign at the 1st month after surgery in high-FO group was 15.2%(7/46),which was significantly lower than 39.1%(18/46)in low-FO group,and the difference was significant(x2=7.324,P<0.05).The used time of walking aids was shortened by 37%[(13.5±3.1)d]in high-FO group,which was significantly shorter than[(21.4±4.9)d]in low-FO group,and the difference was significant(t=9.127,P<0.05).Conclusion:Spiral CT-guided FO precision reconstruction can significantly enhance postoperative recovery quality of joint function of patients who undergo percutaneous-assisted superior capsulotomy approach for THA,and reduce the risks of abnormal gait and dislocation.
7.Heterologous Expression,Purification and Enzymatic Characterization of Xylitol Dehydrogenase from the Thermophilic Fungus Talaromyces emersonii
Er MENG ; Cong QU ; Ke YI ; Hui-Min LI ; Xin-Yi DUAN ; Zhe-Yuan ZHANG ; Shao-Long HE ; Yu-Tao LUO ; Lei WU ; Dong-Yi ZHANG ; Chang-Jun LIU
Chinese Journal of Biochemistry and Molecular Biology 2025;41(7):1007-1018
The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose-catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16 ℃ in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni-NTA affinity column.Size-exclusion chromatography and SDS-PAGE analysis demonstrated that the puri-fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD+as a coenzyme to NADP+.The optimal temperature and pH of the TeXDH were 40 ℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26%of the initial enzyme activity,while the divalent metal ions Mg2+or Ca2+could recover the enzyme activity of TeXDH,reaching 103.32%and 110.69%of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn2+,Ni2+,Cu2+,Zn2+,Co2+,and Cd2+significantly inhibited the activity of TeXDH.ICP-MS and molecular doc-king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn2+ions and 1 mol/L Mg2+ion.Further-more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors.
8.Analysis of Clinical Characteristics and Prognostic Risk Factors of Mycoplasma pneumoniae Pneumonia in Adults of Different Age Groups
Jia ZHU ; Tao-mei ZHANG ; Qing-liu TAN ; Cong-hui CHEN ; Ya-nan MA
Progress in Modern Biomedicine 2025;25(15):2472-2477
Objective:To explore the clinical characteristics and prognostic risk factors of Mycoplasma pneumoniae pneumonia(MPP)in adults across different age groups,providing evidence for age-stratified management strategies.Methods:A retrospective analysis was conducted on 80 MPP patients admitted to the Respiratory Department of a hospital between January 2023 and December 2024.Patients were divided into three groups based on age:young adults(18-40 years),middle-aged adults(41-60 years),and elderly adults(≥ 61 years).Demographic features,clinical indicators,and mixed infections were analyzed.Univariate and multivariate Logistic regression were used to identify risk factors for disease severity.Results:The severity rate was significantly higher in the elderly group(41.2%)compared to the young adult group(7.1%)and middle-aged group(20.0%)(P=0.022).Elderly patients also exhibited significantly higher rates of underlying diseases(chronic lung disease:35.3%vs.3.6%in young adults),elevated inflammatory markers(C-reactive protein:68.3±19.5 mg/L vs.32.5±8.4 mg/L in young adults),mixed infections(52.9%vs.14.3%),and prolonged hospital stays(8.61±2.22 days vs.5.01±1.11 days)(P<0.05).Multivariate analysis identified age(OR=1.79 per 10 years),chronic lung disease(OR=3.25),blood urea nitrogen ≥6 mmol/L(OR=2.44),and mixed infections(OR=4.26)as independent risk factors for severe MPP(P<0.05).Conclusion:Clinical manifestations and prognoses of MPP in adults vary significantly across age groups.Elderly patients are characterized by high mixed infection rates,intense inflammatory responses,and renal function impairment,necessitating individualized monitoring and intervention strategies.
9.Mass Spectrometry-based Identification of GP73 Interacting Proteins Reveals Its Regulatory Role on RNA Splicing Efficiency
Chang ZHANG ; Mu-Yi LIU ; Meng-Xin YANG ; Lu-Ming WAN ; Hui ZHONG ; Cong-Wen WEI
Chinese Journal of Biochemistry and Molecular Biology 2025;41(3):404-414
Protein-protein interactions play an extremely important role in the biochemical functions of cells,and in-depth analysis of protein interactions is the key to understanding cellular life activities.In this study,we systematically mined the interacting proteins of Golgi protein 73(GP73)using classical immunoprecipitation combined with mass spectrometry,and sought to further analyze the molecular func-tion of GP73.Hepatocellular carcinoma cell line HepG2 was selected,and a stable cell line overexpress-ing GP73-3Flag was constructed using lentiviral infection technology.A total of 78 high-confidence GP73 interacting proteins were identified by immunoprecipitation coupled with mass spectrometry.Bioinformat-ics analyses suggested that GP73 interacted with nearly 40 cytosolic proteins and participated in the bio-logical processes of RNA transport,splicing,and translation.Further immunofluorescence and cytosolic protein isolation experiments confirmed the cytosolic localization of GP73 in a variety of tumor cells.Based on the 78 interacting proteins,we further screened protein interaction networks related to mRNA splicing and verified the existence of interactions between GP73 and seven proteins,including HNRN-PH3,SMN1,RBM14,andNCBP1,by co-immunoprecipitation experiments.In addition,minigene spli-cing assay results indicated that GP73 inhibited the splicing efficiency of pre-mRNA by cells.This study contributes to the expansion of knowledge regarding the function of GP73 and aids in elucidating its criti-cal role in cell biology and its potential association with diseases.
10.Heterologous Expression,Purification and Enzymatic Characterization of Xylitol Dehydrogenase from the Thermophilic Fungus Talaromyces emersonii
Er MENG ; Cong QU ; Ke YI ; Hui-Min LI ; Xin-Yi DUAN ; Zhe-Yuan ZHANG ; Shao-Long HE ; Yu-Tao LUO ; Lei WU ; Dong-Yi ZHANG ; Chang-Jun LIU
Chinese Journal of Biochemistry and Molecular Biology 2025;41(7):1007-1018
The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose-catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16 ℃ in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni-NTA affinity column.Size-exclusion chromatography and SDS-PAGE analysis demonstrated that the puri-fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD+as a coenzyme to NADP+.The optimal temperature and pH of the TeXDH were 40 ℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26%of the initial enzyme activity,while the divalent metal ions Mg2+or Ca2+could recover the enzyme activity of TeXDH,reaching 103.32%and 110.69%of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn2+,Ni2+,Cu2+,Zn2+,Co2+,and Cd2+significantly inhibited the activity of TeXDH.ICP-MS and molecular doc-king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn2+ions and 1 mol/L Mg2+ion.Further-more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors.

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